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| 1 | +package com.flit.protoc.gen.server.jakarta; |
| 2 | + |
| 3 | +import com.flit.protoc.gen.server.BaseGenerator; |
| 4 | +import com.flit.protoc.gen.server.TypeMapper; |
| 5 | +import com.flit.protoc.gen.server.Types; |
| 6 | +import com.google.common.net.MediaType; |
| 7 | +import com.google.protobuf.DescriptorProtos; |
| 8 | +import com.google.protobuf.DescriptorProtos.MethodDescriptorProto; |
| 9 | +import com.google.protobuf.compiler.PluginProtos.CodeGeneratorResponse.File; |
| 10 | +import com.squareup.javapoet.AnnotationSpec; |
| 11 | +import com.squareup.javapoet.ClassName; |
| 12 | +import com.squareup.javapoet.FieldSpec; |
| 13 | +import com.squareup.javapoet.MethodSpec; |
| 14 | +import com.squareup.javapoet.ParameterSpec; |
| 15 | +import com.squareup.javapoet.TypeSpec; |
| 16 | +import com.squareup.javapoet.TypeSpec.Builder; |
| 17 | +import java.util.Collections; |
| 18 | +import java.util.List; |
| 19 | +import javax.lang.model.element.Modifier; |
| 20 | + |
| 21 | +public class RpcGenerator extends BaseGenerator { |
| 22 | + |
| 23 | + static final ClassName PATH = ClassName.bestGuess("jakarta.ws.rs.Path"); |
| 24 | + static final ClassName POST = ClassName.bestGuess("jakarta.ws.rs.POST"); |
| 25 | + static final ClassName CONTEXT = ClassName.bestGuess("jakarta.ws.rs.core.Context"); |
| 26 | + static final ClassName HttpServletRequest = ClassName.bestGuess("jakarta.servlet.http.HttpServletRequest"); |
| 27 | + static final ClassName HttpServletResponse = ClassName.bestGuess("jakarta.servlet.http.HttpServletResponse"); |
| 28 | + |
| 29 | + private final Builder rpcResource; |
| 30 | + private final boolean passRequest; |
| 31 | + |
| 32 | + RpcGenerator( |
| 33 | + DescriptorProtos.FileDescriptorProto proto, |
| 34 | + DescriptorProtos.ServiceDescriptorProto service, |
| 35 | + String context, |
| 36 | + TypeMapper mapper, |
| 37 | + boolean passRequest |
| 38 | + ) { |
| 39 | + super(proto, service, mapper); |
| 40 | + String prefix = getContext(context); |
| 41 | + this.passRequest = passRequest; |
| 42 | + this.rpcResource = TypeSpec.classBuilder(getResourceName(service)) |
| 43 | + .addModifiers(Modifier.PUBLIC) |
| 44 | + .addAnnotation( |
| 45 | + AnnotationSpec.builder(PATH).addMember("value", "$S", |
| 46 | + prefix + "/" + (proto.hasPackage() ? proto.getPackage() + "." : "") + service |
| 47 | + .getName()).build()); |
| 48 | + addInstanceFields(); |
| 49 | + addConstructor(); |
| 50 | + service.getMethodList().forEach(this::addHandleMethod); |
| 51 | + } |
| 52 | + |
| 53 | + private void addConstructor() { |
| 54 | + rpcResource.addMethod(MethodSpec.constructorBuilder() |
| 55 | + .addModifiers(Modifier.PUBLIC) |
| 56 | + .addParameter(getServiceInterface(), "service") |
| 57 | + .addStatement("this.service = service").build()); |
| 58 | + } |
| 59 | + |
| 60 | + private void addHandleMethod(MethodDescriptorProto mdp) { |
| 61 | + ClassName inputType = mapper.get(mdp.getInputType()); |
| 62 | + ClassName outputType = mapper.get(mdp.getOutputType()); |
| 63 | + rpcResource.addMethod(MethodSpec.methodBuilder("handle" + mdp.getName()) |
| 64 | + .addModifiers(Modifier.PUBLIC) |
| 65 | + .addAnnotation(POST) |
| 66 | + .addAnnotation(AnnotationSpec.builder(PATH) |
| 67 | + .addMember("value", "$S", "/" + mdp.getName()) |
| 68 | + .build()) |
| 69 | + .addParameter(ParameterSpec.builder(HttpServletRequest, "request") |
| 70 | + .addAnnotation(CONTEXT).build()) |
| 71 | + .addParameter(ParameterSpec.builder(HttpServletResponse, "response") |
| 72 | + .addAnnotation(CONTEXT).build()) |
| 73 | + .addException(Types.Exception) |
| 74 | + .addStatement("boolean json = false") |
| 75 | + .addStatement("final $T data", inputType) |
| 76 | + .beginControlFlow("if (request.getContentType().equals($S))", MediaType.PROTOBUF.toString()) |
| 77 | + .addStatement("data = $T.parseFrom(request.getInputStream())", inputType) |
| 78 | + .nextControlFlow("else if (request.getContentType().startsWith($S))", "application/json") |
| 79 | + .addStatement("json = true") |
| 80 | + .addStatement("$T.Builder builder = $T.newBuilder()", inputType, inputType) |
| 81 | + .addStatement("$T.parser().merge(new $T(request.getInputStream(), $T.UTF_8), builder)", |
| 82 | + Types.JsonFormat, |
| 83 | + Types.InputStreamReader, |
| 84 | + Types.StandardCharsets) |
| 85 | + .addStatement("data = builder.build()") |
| 86 | + .nextControlFlow("else") |
| 87 | + .addStatement("response.setStatus(415)") |
| 88 | + .addStatement("response.flushBuffer()") |
| 89 | + .addStatement("return") |
| 90 | + .endControlFlow() |
| 91 | + // route to the service |
| 92 | + .addStatement(getRouteToService(), outputType, mdp.getName()) |
| 93 | + .addStatement("response.setStatus(200)") |
| 94 | + // send the response |
| 95 | + .beginControlFlow("if (json)") |
| 96 | + .addStatement("response.setContentType($S)", MediaType.JSON_UTF_8.toString()) |
| 97 | + .addStatement("response.getOutputStream().write($T.printer().omittingInsignificantWhitespace().print(retval).getBytes($T.UTF_8))", |
| 98 | + Types.JsonFormat, |
| 99 | + Types.StandardCharsets) |
| 100 | + .nextControlFlow("else") |
| 101 | + .addStatement("response.setContentType($S)", MediaType.PROTOBUF.toString()) |
| 102 | + .addStatement("retval.writeTo(response.getOutputStream())") |
| 103 | + .endControlFlow() |
| 104 | + .addStatement("response.flushBuffer()") |
| 105 | + .build()); |
| 106 | + } |
| 107 | + |
| 108 | + private String getRouteToService() { |
| 109 | + if (passRequest) { |
| 110 | + return "$T retval = service.handle$L(request, data)"; |
| 111 | + } else { |
| 112 | + return "$T retval = service.handle$L(data)"; |
| 113 | + } |
| 114 | + } |
| 115 | + |
| 116 | + private ClassName getResourceName(DescriptorProtos.ServiceDescriptorProto service) { |
| 117 | + return ClassName.get(javaPackage, "Rpc" + service.getName() + "Resource"); |
| 118 | + } |
| 119 | + |
| 120 | + private void addInstanceFields() { |
| 121 | + rpcResource.addField(FieldSpec.builder(getServiceInterface(), "service") |
| 122 | + .addModifiers(Modifier.PRIVATE, Modifier.FINAL).build()); |
| 123 | + } |
| 124 | + |
| 125 | + @Override |
| 126 | + public List<File> getFiles() { |
| 127 | + return Collections.singletonList(toFile(getResourceName(service), rpcResource.build())); |
| 128 | + } |
| 129 | +} |
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